SAN DIEGO, March 21, 2016 – Ambrx and Zhejiang Medicine Co. Ltd. (ZMC) announced today that they initiated First-In-Human phase I clinical trial with ARX788, Ambrx’s most advanced internally developed site-specific antibody drug conjugate (ADC) targeting Her2. Ambrx ARX788 may hold the potential for a broader patient population than the currently available Her2 targeting therapies. The multicenter study will be conducted at several sites within Australia and New Zealand. The primary end point is safety and tolerability, and the pharmacokinetics of ARX788 will also be evaluated. The application for the initiation of clinical trial in China was submitted to the China FDA early this year.

“We are very happy about the collaboration with ZMC. This is an important milestone for this partnership,” said Alex Qiao, Chief Executive Office at Ambrx. “This is the first exciting step to demonstrate the clinical application of our proprietary EuCODE™ technology for the improvements of cancer patient lives. This is not only an important milestone for our ARX788 program, but also is a major event for our unique site specific protein conjugation technology platform as we hope to leverage this same technology to develop ADC drugs for a number of different cancers.”

“We are very happy to see ARX788 entering into clinical trial,” Said Mr. Chunbo Li, chairman of ZMC. “We hope our collaboration with Ambrx in this innovative program will eventually benefit cancer patients around the world.”

About AmbrxAmbrx®, Inc. is a biopharmaceutical company with a mission to deliver breakthrough protein therapeutics using an expanded genetic code. Unlike conventional conjugation techniques that create a mixture of suboptimal molecules, Ambrx technology combines site specific conjugation with proprietary linkers, payloads and pharmacokinetic extenders to create a single molecular species that is optimized for safety, efficacy and biophysical properties. We call this process Protein Medicinal Chemistry™.

Protein Medicinal Chemistry™ can optimize any protein or antibody to create potentially best-in-class therapeutics such as long-acting proteins, bi-specifics and antibody drug conjugates. The Ambrx advantage allows us to safely and effectively target cytotoxic agents or recruit effector function to tumor cells (oncology) or modulate biological pathways implicated in disease areas such as autoimmune, metabolic and cardiovascular.

At Ambrx, we are dedicated to assembling and developing an exceptional team and a novel technology to create the next generation of protein-based medicines. For additional information, visit www.ambrx.com.

About Zhejiang Medicine Co. Ltd.Zhejiang Medicine Co. Ltd. (ZMC) is a major China-based pharmaceutical company listed on the Shanghai stock exchange. It is a leading global manufacturer of fat-soluble vitamins and bacteria-resistant antibiotics. ZMC’s products are exported to the United States and many EU countries. In 2015, total revenue reached 4.5 billion RMB. ZMC has strong capabilities in technology innovation and new drug R&D and has received the National High-Tech Enterprise and Model Innovation Enterprise awards in China. ZMC has a national-level R&D center and post-doctorate R&D sponsorship. Three ZMC research projects were awarded second prize in the National Technology Advancement competition and one was awarded second prize in the National Technology Innovation competition. To date, ZMC has 169 issued patents, including 31 global patents, and has four class 1 drugs in completed or ongoing clinical trials.